Error ‘1635: This patch package could not be opened’ When Installing Adobe Reader 8.1

Error ‘1635: This patch package could not be opened. Verify that the patch package exists and that you can access it, or contact the application vendor to verify that this is a valid Windows Installer patch package.‘ when you attempt to install Reader 8 on a windows XP or Vista machine can be fixed with the following steps.

 

1. Download The Windows Install Cleanup Utility from Microsoft by clicking the link below

   Windows Install Cleanup Utility

2. Install the Windows Install Cleanup Utility. Either select run after downloading or find where you downloaded the file to and double click on it. The file name is MSICUU2.exe, short for MicroSoft Installer Cleanup Utility 2.
3. Run the Windows Install Cleanup Utility. After installing it should be located in your ‘all programs’ list. Go to Start then All Programs then click on Windows Install Cleanup Utility
4. Find the version of Reader you are unable to remove, select it and then hit ‘Remove’
5. Install Reader

You should keep in mind that you should only use the Windows Install Cleanup Utility if you are unable to remove the program through add/remove programs. Also, this doesn’t uninstall the program but allows Adobe Reader to overwrite the past version. That being said, if you get the 1635 error; this is how you take care of it.